Pendulum valve assembly

Abstract

A valve assembly including a housing having an opening defined by a valve seat, a valve body movable within the housing between a completely opened position disengaged from the valve seat and a completely closed position engaging the valve seat, and a sleeve movable longitudinally along, and rotatably about, a longitudinal axis. The sleeve is connected to the valve body so that the valve body can rotate and move longitudinally with the sleeve. One of the housing and the sleeve includes a cam surface, and the other of the housing and the sleeve includes a cam follower received by the cam surface. A rotatable shaft is in threaded engagement with the sleeve so that rotation of the shaft causes at least one of rotation and longitudinal movement of the sleeve against the cam follower.

Description

FIELD OF THE INVENTIONThe present invention relates generally to pendulum or gate valve assemblies, and more particularly to a pendulum valve assembly including a new and improved arrangement providing both rotary and axial motion to a flapper of the pendulum valve assembly.BACKGROUND OF THE INVENTIONA pendulum valve assembly generally includes a housing containing a pendulum valve and including an interior space and a pair of openings through which gaseous fluid can enter and exit the interior space. Pendulum valve assemblies are particularly useful in high purity gas delivery systems, such as those used in semiconductor manufacturing or other thin film coating processes. As its name implies, a pendulum valve pivots between open and closed positions, and includes a valve body, which is usually provided as a disk or flapper, connected to a rotatably shaft by a pivot arm. In a completely opened position the disk of the pendulum valve is moved out of the flow path defined by the openi...

AI Technical Summary

Benefits of technology

The present invention provides a new and improved valve assembly including a housing having an interior space and an opening through which fluid can enter and exit the interior space, a valve body movable within the interior space between a completely opened position allowing fluid flow through the opening and a completely closed position preventing fluid flow through the opening, and a sleeve movable longitudinally along, and rotatably about, a longitudinal axis. The sleeve is connected to the valve body so that the valve body can rotate with the sleeve about the longitudinal axis between the completely opened position and an intermediate position where the valve body is substantially aligned with the opening but spaced longitudinally therefrom, and so that the valve body can move longitudinally with the sleeve between the intermediate position and the completely closed position.

Among other aspects and advantages of the present invention, the valve body of the valve assembly is provided with both rotational and longitudinal movement between the closed and the opened position. The valve assembly of the present invention also provides a resolution of the longitudinal movement that can be chosen independently of a resolution of the rotational movement of the valve body. Moreover, the present invention provides a new and improved pendulum valve assembly that supplies a more controllable and consistent change in conductance through the valve assembly during opening and closing of the valve.

Problems solved by technology

Thus, the overall conductance includes very little change in flow followed by a very rapid change in flow (and vice versa as the gate is closed), which results in poor control of flow (conductance) in this operating range of the valve.

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